An algorithm which allows digits of a given number to be calculated without requiring the computation of earlier digits. The BBP formula for pi is the best-known such algorithm, but an algorithm also exists for e.
Plouffe (2022) gives a particularly simple digit-extraction algorithm for the decimal digits of 
by defining
 | (1) |
Then the 
th digit to the right of the decimal point of 
for 
is given by
 | (2) |
where 
is the integer part and 
is the fractional part. Similar formulas can be obtained using
 | (3) |
and
 | (4) |
where 
is an Euler number, which gives a base-9 (or binary) digit extraction formula (Plouffe 2022). Similar results can be also obtained for 
, 
, 
, 
, 
, and 
(Plouffe 2022).
'th Decimal Digit or Binary of 
and 
."